1. Field of the Invention
The present invention relates to a device for mixing air and water in a water purifier, said device comprising a water inlet pipe, which is connected to a water source and which extends into a water purifier tank, and an air inlet pipe extending coaxially inside the water pipe, one end of the air pipe being positioned outside the tank and the other end being positioned inside the water pipe to form an annular gap between the end of the air pipe and the inner wall of the water pipe, and the water pipe having a mixing portion which extends from the annular gap to the water pipe mouth in the tank.
2. Description of the Related Art
Aerating drinking-water is a prior-art method of reducing the amount of impurities in the water. Such water purifiers are disclosed in e.g. Swedish Patent 8900169-7 and Swedish Patent Applications 9303412-2, 9402780-2 and 9403643-1. In all the constructions shown in these publications, use is made of the ejector principle for admixing air to drinking-water which is pumped into a tank from a drinking-water source. The amount of air, actually the oxygen in the air, which is blended with the water affects the purifying process. The more oxygen blended with the water, the better the purification.
A technique of increasing the oxygen content in the water is to let the water-air mixture from the ejector flow out in the tank below the water surface in the tank. This is disclosed in SE-9403643-1. A stirring effect is accomplished in the tank, which is advantageous for the blending of oxygen with the water. In tests, it has been found that also an increased intake of air through the air inlet pipe is achieved by the flowing-out taking place below the water surface.
In spite of the increased air intake and the use of said stirring effect, the purification of the water will deteriorate owing to the fact that air and water mix worse as the flow rate increases.